Blender is rendering my short animation too slow!
Welcome to the hard reality of 3d Rendering: rendering takes time, a lot of it.
The more detailed and complex the scene, the more resources are needed to render.
You have three options:

Use more powerful hardware, more processors, faster processors, more GPUs and lots and lots of RAM.

Use a render farm, that will render all the frames using many computers, freeing your own. If every frame takes 4 hours to render  and you use 120 computers simultaneously, then you can render 120 frames in 4 hours!
Or use cloud computing to have access to higher specs hardware. Do a search for Amazon elastic compute clud, or other similar solutions.

Adjust your expectations to the hardware available to you. Create and optimize your scenes in a way that you can render them within your means, and in a reasonable time.